In recent years, distributing of advertisements to smart devices by using digital watermarking, or the like has been spreading.
As one example of a digital watermarking technology, a digital watermark embedding device is known that embeds watermark information into moving image data in such a way that the moving image data does not deteriorate in image quality (see, for example, Patent Document 1). The digital watermark embedding device periodically changes the area of a watermark pattern superimposed onto respective images in the moving image data along time series in accordance with a value of a symbol included in digital watermark information. The digital watermark embedding device corrects values of respective pixels included in a region in which each of the images overlaps a watermark pattern that corresponds to the image, in accordance with a prescribed value that pixels included in the watermark pattern have.
An optical radio communication device is also known that precisely receives information transmitted from a light source that performs optical radio communication (see, for example, Patent Document 2). The optical radio communication device detects an image of a light source in a photographed image obtained by photographing one or more light sources including an optical radio communication light source, and obtains position information of an image of the optical radio communication light source from the detected image of the light source. The optical radio communication device obtains information relating to an incident position in which light output from the optical radio communication light source is made incident on the basis of the position information of the image of the optical radio communication light source, and also obtains information that is transmitted from the optical radio communication light source via optical radio communication in the incident position.
Patent Document 1: Japanese Laid-open Patent Publication No. 2012-142741
Patent Document 2: Japanese Laid-open Patent Publication No. 2011-009803